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Blazars, a class of highly variable active galactic nuclei, sometimes exhibit Orphan $gamma$-ray flares. These flares having high flux only in $gamma$-ray energies do not show significant variations in flux at lower energies. We study the temporal and spectral profile of these Orphan $gamma$-ray flares in detail from three $gamma-ray$ bright blazars, 3C 273, PKS 1510-089 and 3C 279 and also their simultaneous broadband emissions. We find that the variability timescales of the Orphan $gamma$-ray flares were $(0.96pm0.28)$ days, $(3.12pm2.40)$ hr and $(2.16pm0.72)$ hr, for 3C 273, PKS 1510-089 and 3C 279, respectively. The broadband spectral energy distributions (SEDs) during these flares have been modelled with a leptonic model from two emission regions. This model suggests that Orphan $gamma$-ray flares might have originated from inverse Compton scattering of relativistic electrons by the seed photons from the broad-line region or dusty torus, which is the first region. While the second broader region, lying further down the jet, could be responsible for X-ray and radio emissions. The possible locations of these emission regions in the jets of the three sources have been estimated from SED modelling.
Blazars exhibit flares across the entire electromagnetic spectrum. Many $gamma$-ray flares are highly correlated with flares detected at longer wavelengths; however, a small subset appears to occur in isolation, with little or no correlated variabili
Gamma Ray Bursts are detectable in the gamma-ray band if their jets are oriented towards the observer. However, for each GRB with a typical theta_jet, there should be ~2/theta_jet^2 bursts whose emission cone is oriented elsewhere in space. These off
I present a systematic study of gamma-ray flares in blazars. For this purpose, I propose a very simple and practical definition of a flare as a period of time, associated with a given flux peak, during which the flux is above half of the peak flux. I
We present predictions of centimeter and millimeter radio emission from reverse shocks in the early afterglows of gamma-ray bursts with the goal of determining their detectability with current and future radio facilities. Using a range of GRB propert
GRB 131108A is a bright long Gamma-Ray Burst (GRB) detected by the Large Area Telescope and the Gamma-ray Burst Monitor on board the textit{Fermi Gamma-ray Space Telescope}. Dedicated temporal and spectral analyses reveal three $gamma$-ray flares dom